1. Field of the Invention
The present invention relates to a system and method for repairing soft tissue and, more particularly, to a system and method for repairing torn meniscal tissue.
2. Background of the Invention
The surgical repair of soft tissue has typically been performed through incisions in the body to expose the area under repair followed by the application of sutures, staples, or other surgical fasteners. The use of such conventional devices typically requires a highly skilled surgeon to perform the repair and complete immobilization of the surgical area following the repair procedure. More recently, the use of arthroscopic and endoscopic techniques and equipment has reduced the size and depth of the incision required to perform the repair.
Surgical repair of cartilage and muscle adjacent a joint such as the knee often requires a high degree of skill on the part of the surgeon to reduce damage to adjacent nerves, blood vessels, cartilage, muscles, and tendons. In particular, the repair of the fibrocartilage disks within the knee known as the menisci, attached peripherally to the joint capsule, requires precision to avoid such damage.
In the past, meniscal surgery has included procedures for partial to complete removal of a torn meniscus, as well as attempts to surgically suture, staple, or fasten the tear in the meniscus to allow for healing. Other techniques have included removal of portions of the meniscus to arrest the spread of the tear.
Several devices and procedures have been proposed for the repair of meniscal tissue, especially the meniscus of the knee. In one arthroscopic procedure, a pair of surgical needles are inserted through cannulae into the knee on opposite sides of the tear in the meniscus to be repaired. The needles are linked by a single suture which is pushed down through the cannulae and across the tear. An incision is made in the skin at the point where the needles exit the knee joint so that the leading edge of each needle may be grasped and pulled through the joint. After the needles are removed, the ends of the sutures are tied outside the skin so that a horizontal suture is created in the meniscus. This time-consuming procedure is repeated for the placement of as many sutures as necessary to repair the meniscal tear.
U.S. Pat. No. 4,873,976 to Schreiber discloses surgical fasteners for repairing tears in body tissue, particularly the meniscus of the knee joint. The fastener has a base member for seating against the body tissue, a shaft upstanding from the base member for inserting into the tissue and across the tear, and at least one barb for locking the shaft in place, holding both sides of the tear together. The Schreiber fastener is a single unit, i.e., a one-piece prefabricated element of predetermined dimensions. As such, the shaft portion which is inserted across the tear has a fixed length which cannot be modified to provide adjustable sizing or tensioning across the tear.
Other fasteners for repairing a torn meniscus are shown in U.S. Pat. Nos. 5,059,206 and 4,895,148. Like the faster shown in the Schreiber patent, these fasteners do not provide means for adjusting length or the tension across the meniscal tear.
U.S. Pat. No. 4,741,330 to Hayhurst describes a method and apparatus for anchoring and manipulating cartilage within a joint during arthroscopic surgery. In Hayhurst, the cartilage is pierced by a hollow needle containing an elongate anchoring device with an attached suture. The suture passes through the bore of a hollow tube, positioned within the hollow needle behind the anchoring device. The tube is used to push the anchoring device out of the needle tip behind the cartilage to be anchored. In this manner, the anchoring device is intended to lodge in or beyond the cartilage at a nonparallel angle to the suture, thereby anchoring the suture to the cartilage. The needle and the tube may be withdrawn and the cartilage manipulated by appropriate tension on the suture. This device suffers from the disadvantage that the elongate anchoring device must change position during insertion into the cartilage from a first orientation within the hollow needle to a second orientation in the tissue.
In a separate embodiment, the Hayhurst patent describes a device for anchoring a suture to bone. Barb-like projections are provided on the exterior of an anchoring device to which is attached a suture. The anchoring device is inserted into a pre-drilled hole in bone to which tendons or ligaments are to be attached. A retainer including resilient suture-engaging edges and corners is slidable along the suture in one direction and grips the suture to resist sliding of the retainer in the opposite direction. Because a hole must be drilled in the bone prior to the insertion of the anchor, this device is not useful for repairing tears in soft body tissue.
There is a need in the art for a system for repairing soft tissue which comprises a suture anchoring member having a suture member attached thereto which is inserted across torn tissue without the need to change the orientation of the anchoring member. The system, preferably dimensioned and configured for arthroscopic and endoscopic use, should include a retaining member for retaining the end of the suture member opposite the suture anchoring member. There is a further need in the art for a system for repairing soft tissue in which a suture member attached to an anchoring member is adjustably engageable with a suture retaining member so that the length and tension of the suture member may be selected by the user during the surgical procedure. Such a system could be used for repairing soft tissue, especially in hard to access regions of the body such as the meniscus of the knee joint.